Thwaites, a notoriously unstable glacier in West Antarctica, is cracking and disintegrating, spelling bad news for global sea level rise. Efforts are being made to understand the geometry and chemistry of Thwaites, which is about the size of Florida, to measure the effect that warming waters and climate change may have on it.
An 11-foot tube-like underwater robot called Icefin is giving us a detailed look deep under the ice at how the vulnerable Antarctic ice shelf is melting. In the form of two articles published this week in the journal NatureIcefin has provided relevant details about the conditions under icy water.
The torpedo-like Icefin was first developed at Georgia Tech, and the first prototype of the robot dates back to 2014. But it has since found a new home at Cornell University. This robot is able to characterize environments under the ice using the suite of sensors it carries. It is equipped with HD cameras, laser ranging systems, sonar, Doppler current profilers, single beam altimeters (to measure distance) and instruments for measuring salinity, temperature, dissolved oxygen, pH and organic matter. Its range is impressive: It can descend to a depth of 3,280 feet and squeeze through narrow cavities in the ice shelf.
As the Icefin is modular, it can be broken down, adapted and assembled according to the needs of the mission. Scientists can remotely control Icefin’s trajectory, or let it go on its own.
Icefin is not alone in this cold water. The journey is part of the International Thwaites Glacier Collaboration (ITGC), which includes other radars, sensors and vehicles such as Boaty McBoatface.
(Related: The ‘doomsday glacier’ cracks and changes. AI can help us understand how.)
In 2020, through a nearly 2,000-foot-deep borehole drilled into the ice, Icefin ventured out across the ocean to the critical point where the Thwaites Glacier joins the Amundsen Sea and the ice begins to flow. Data collected by Icefin, and analyzed by human scientists, showed that the glacier had retreated up the seafloor, thinned at the base and melted rapidly outwards. In addition, the shapes of certain cracks in the ice help funnel in warm ocean currents, causing parts of the glacier to melt faster than previously expected.
These new insights, as daunting as they are, could improve older models that have been used to predict the changes in the Thwaites, and in the rate of possible sea-level rise if it collapses.
“Icefin collects data as close to the ice as possible in places that no other tool can currently reach,” Peter Washam, a Cornell University researcher who led analysis of Icefin data used to calculate melt rates, said in a press release. “It shows us that this system is very complex and requires a reassessment of how the ocean melts the ice, especially in a place like Thwaites.”
Outside of Thwaites, you can find Icefin monitoring the ecosystems of the Arctic Ocean around Antarctica’s McMurdo Research Station, or helping astrobiologists understand how life originated in ocean worlds and their biospheres.
Learn more about Icefin below: